Thursday, July 18, 2013

More Math, Less Fighting #2

Here's one from the beginning of The Moscow Puzzles by Boris A. Kordemsky.
Moving Checkers 
Place 6 checkers on a table in a row, alternating them black, white, black, white, [black, white.] 
Leave a vacant place large enough for 4 checkers on the left. 
Move the checkers so that all the white ones will end on the left, followed by all the black ones. The checkers must be moved in pairs, taking 2 adjacent checkers at a time, without disturbing their order, and sliding them to a vacant place. To solve this problem, only three such moves are necessary. ... 
If no checkers are available, use coins, or cut pieces out of paper or cardboard.
Or use paperclips or post-it notes or whatever. Solution from the book to appear in the comments of this post tomorrow.

30 comments:

rhhardin said...

You could play same sex checkers with all pieces the same color.

AllenS said...

I made a donation. Thank you people for your time and effort to gather the old crowd together for a chance to comment.

rhhardin said...

Trevon's mother thinks Trevon got killed for walking too slowly.

I thought it was for beating the shit out of Zimmerman.

It's male black youth culture meets concealed carry.

DADvocate said...

Can't solve the problem. My checkers are black and red.

rhhardin said...

The six utility company trucks are back, and some hole improvement has been done.

Now everybody has disappeared but the trucks remain, marked with orange traffic cones.

There is no men working sign.

rhhardin said...

I only know one math puzzle. It's very old. The prices are out of date.

Peter DeVries posted the solution in Vale of Tears.

Three salesmen rent a room for the night for $30.

The desk clerk realizes it's only a $25 room, so sends the bellhop up to return $5.

The bellhop realizes that there's no way three guys can split $5, so he pockets $2 and returns the rest.

The men paid $27 for the room. The bellhop kept $2, making $29.

Where's the other dollar?

rhhardin said...

Vale of Laughter, not Vale of Tears.

Shouting Thomas said...

OK, I'll comment once.

I ceased commenting on Althouse before the purge. No particular reason. Mainly, just tired of the perfesser directing my thoughts. Decided I'd think my own for a while.

I visit Althouse occasionally. Not much use without the comments. The best thing about the site was the prim and ever so reasonable perfesser meeting the unwashed masses.

The wild comments boosted the site stats, but Althouse doesn't need that anymore, and I can see that maintaining order was becoming a pain in the ass. It was even a little too rough house for me, and I'm a real bastard.

The Dude said...

"Move the checkers so that all the white ones will end on the left, followed by all the black ones."

RAAAACIIIISSSS!

rhhardin said...

What is Althouse up to *new tab* *click*

It's a report of a not bad but a little overdone Meade joke.

A marriage that will last forever.

Karen of Texas said...
This comment has been removed by the author.
Karen of Texas said...
This comment has been removed by the author.
rhhardin said...

Dagen McDowell said on Imus that the dirty version of Blurred Lines had a girl with really really great breasts. She's taking a pic to her plastic surgeon.

Blurred Lines? Google is your friend.

The NSFW (I guess, because of tits) youtube version is here.

I can't tell which girl she means.

All women out and about and naked look ridiculous, mostly. But apparently not to women! There's a preferred if mysterious shape that they imagine they need.

In a sexual situation, it's another matter. Then it's second base, to guys.

The real feminine operation is concealing that nothing is concealed.

Eric the Fruit Bat said...

Those are nice breasts.

Lem the artificially intelligent said...

You are welcome AllenS.

Hazy Dave said...

The only loophole I see to the math problem is whether the assumption of 10 "spaces" - four blank, then six checkers ought to be made. I think to solve, you just have to say that there are plenty of empty spaces to the right of the six checkers, too. And "adjacent" doesn't mean "right next to", only "no other checkers in between". Thusly:

....BWBWBW....
WB..BWB..W....
W....WB..W..BB
W........WWBBB

Freeman Hunt said...

You can solve it with no extra spaces to the right, I believe.

Icepick said...

I thought this one a little too easy. I'll see if I can dig out something from out of my books.

Also, look for Sam Loyd puzzles: e.g. here. At one time America's greatest puzzle maker, and most if not all of his stuff should be public domain.

Icepick said...

My solution post here.

No empty space to the right? Let me see....

Chip Ahoy said...

I could not play this game because the instructions are not clear.

6 checkers on a table in a row bwbwbw Fine. There's my row.

vacant place for 4 checkers on the left. Not fine. The left is entirely empty. There is only one row. You didn't say anything about righ/left until now. What was on the left to begin with, air? An empty row? What?

See? This right here is an example of never taking directions from a woman.

Can you show me the directions in sign language?

Although I am certain I can play this game it's like get everybody off the island safely with one single boat without the dangerous one eating the weak one until the task is complete or something.There are variations of this.

It's very much like the match game where you reverse the direction of the fish in so many moves.

My alltime favorite computer game had such a challenge as this in it.

I found that game by walking past it at a friend of friend of friend who lives on... some remote fellow had it on the computer screen as two of us walked by. It was pretty so I asked, "What's this?" Both said, the owner and the other friend answered together, so they played it together earlier, "This is where we're stuck."

You have to match the tiles to get out of the room. There is a whole row to match and a row to match from. They are elaborate inscriptions. Like super fancy writing, and they cannot match them up. That's where they're stuck. Both are.

At a glance.

A glance, I tell you.

One single glance.

And the answer jumps out. Even after I matched them all, they still could not see it and they regarded me mathematical genius. They are mirror images of ordinary Arabic numerals, you dipshits, it's all to do with looking and nothing to do with thinking.

I meant to say precious angels, Arabic numerals, you precious angels.

But that was my favorite game because it has Egyptian dung beetle in it. Pushes a poop ball around a maze that gets increasingly complex. The maze does, not the poop. It's a wonderful game. The the poop drops in a hole and you win.

The part that was similar to this was fill up the industrial tubes with liquid so that they all end up level straight across although exchanges of liquid between tubes is never an amount that makes that simple you have to do counterintuitive filling and draining.

The title of the game, a series of puzzles, has something to do with a Jewel. And it's about a lost culture so everything is mysterious.

Freeman Hunt said...

I have plenty of hard ones. I thought it nice to start with an easier one.

Freeman Hunt said...

Get people interested who might think that they don't like math. Everyone loves math, I think. It's just a big secret what math really is.

Hazy Dave said...

Looks like you have a winner, Icepick. I blame a lack of checkers at my desk.

"I have plenty of hard ones."

I'll bet you do.

Freeman Hunt said...

People are free to race, but I'm not posting these with racing as the intention. Just a little amusement.

Icepick said...

People are free to race, but I'm not posting these with racing as the intention. Just a little amusement.

I'm not racing, though I my post my solutions over at my place. That way I can link to them without actually putting spoilers in the comment threads.

Freeman Hunt said...

Good idea.

Icepick said...

That way I can link to them without actually putting spoilers in the comment threads.

Also? Michael Haz will be less likely to make fun of my mistakes. I'm very sensitive, you know. Like granite. Or pumice.

deborah said...

$30-3-2=25

oneredquilt said...

Ten spaces allowed. Problem doesn't state that the solution requires the pieces to be next to each other:


_ _ _ _ W B W B W B starting positions


_ _ B W W B W _ _ B first move

_ _ B W _ _ W W B B second move

B B B W _ _ W W _ _ third move

Freeman Hunt said...

Solution time. The solution in the book is the same as the solution Icepick came up with here. It is particularly elegant in that everything ends up neatly together.

The posted problem specifies that all white checkers end up on the left, but oneredquilt has also found a solution (see above) for making the white checkers end up on the right.

Fun!

I like this problem because it's one you can give to anyone, and he will enjoy it whether he finds it easy or difficult. It is compelling.